This plant is cultivated sometimes for its fleshy root (red beet), sometimes for its leaves, which are used as a vegetable (white beet), but botanists are generally agreed in not dividing the species. It is known from other examples that plants slender rooted by nature easily become fleshy rooted from the effects of soil or cultivation. The slender-rooted variety grows wild in sandy soil, and especially near the sea in the Canary Isles, and all along the coasts of the Mediterranean Sea, and as far as the Caspian Sea, Persia, and Babylon,[174] perhaps even as far as the west of India, whence a specimen was brought by Jaquemont, although it is not certain that it was growing wild. Roxburgh’s Indian flora, and Aitchison’s more recent flora of the Punjab and of the Sindh, only mention the plant as a cultivated species. It has no Sanskrit name,[175] whence it may be inferred that the Aryans had not brought it from western temperate Asia, where it exists. The nations of Aryan race who had previously migrated into Europe probably did not cultivate it, for I find no name common to the Indo-European languages. The ancient Greeks, who used the leaves and roots, called the species _teutlion_;[176] the Romans, _beta_. Heldreich[177] gives also the ancient Greek name _sevkle_, or _sfekelie_ which resembles the Arab name _selg_, _silq_,[178] among the Nabatheans. The Arab name has passed into the Portuguese _selga_. No Hebrew name is known. Everything shows that its cultivation does not date from more than three or four centuries before the Christian era. The red and white roots were known to the ancients, but the number of varieties has greatly increased in modern times, especially since the beetroot has been cultivated on a large scale for the food of cattle and for the production of sugar. It is one of the plants most easily improved by selection, as the experiments of Vilmorin have proved.[179] +Manioc+—_Manihot utilissima_, Pohl; _Jatropha manihot_, Linnæus. The manioc is a shrub belonging to the Euphorbia family, of which several roots swell in their first year; they take the form of an irregular ellipse, and contain a fecula (tapioca) with a more or less poisonous juice. It is commonly cultivated in the equatorial or tropical regions, especially in America from Brazil to the West Indies. In Africa the cultivation is less general, and seems to be more recent. In certain Asiatic colonies it is decidedly of modern introduction. It is propagated by budding.